215945922978 has 24 divisors (see below), whose sum is σ = 475553045916. Its totient is φ = 70801941600.

The previous prime is 215945922943. The next prime is 215945923003. The reversal of 215945922978 is 879229549512.

215945922978 is a `hidden beast` number, since 2 + 15 + 9 + 4 + 592 + 29 + 7 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 212063013009 + 3882909969 = 460503^2 + 62313^2 .

It is a super-3 number, since 3×215945922978³ (a number of 35 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 98334933 + ... + 98337128.

Almost surely, 2^215945922978 is an apocalyptic number.

215945922978 is an abundant number, since it is smaller than the sum of its proper divisors (259607122938).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

215945922978 is a wasteful number, since it uses less digits than its factorization.

215945922978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196672130 (or 196672127 counting only the distinct ones).

The product of its digits is 32659200, while the sum is 63.

The spelling of 215945922978 in words is "two hundred fifteen billion, nine hundred forty-five million, nine hundred twenty-two thousand, nine hundred seventy-eight".